JPH04217228A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To present a liquid crystal display device of COG type of thin type light in weight small, in size at an inexpensive price with a simple structure and good up/down electrical connection having wiring in only a one side substrate. CONSTITUTION:A device is characterized by sealing a liquid crystal between both substrates 1, 2 while pasting together both the substrates 1, 2 by a seal material 4 of mixing a conduction material 9 having almost the same dimension to a clearance between two upper/lower sheets of the first/second transparent substrates 1, 2, and by mounting a liquid crystal driving LSI3 onto the above- mentioned first transparent substrate 1 by using chip-on-glass technique, further by drawing out a transparent electrode 6 of the above-mentioned second transparent substrate 2 onto the above-mentioned first transparent substrate 1 by the above-mentioned conduction material 9. Since an up/down conduction material- contained seal material 4 of almost the same dimension to the clearance between the substrates, necessary space can be reduced and also obtaining good connection to apply wiring only required to the one substrate, so that the cost of manufacture can be reduced.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a chip-on-glass (hereinafter referred to as COG) type liquid crystal display device.

0002

[Prior Art] A COG type liquid crystal display device has two
Two transparent glass substrates are placed one on top of the other with a predetermined gap in between so that the surfaces provided with transparent electrodes face each other, the liquid crystal is sealed, and an LSI for driving the liquid crystal is mounted on one of the transparent glass substrates as a chip-on-glass. It was installed using technology. In this type of liquid crystal display device, the liquid crystal driving LS
Since the I is directly mounted on a transparent glass substrate, TAB (tape automated bonding) and PCB (printed wiring board) can be omitted, resulting in a thin,
It is lightweight, suitable for miniaturization, and is a promising device for the future. This technique is described in, for example, Japanese Patent Laid-Open No. 171992/1983.

[0003] Also, as a vertical conductive material for display panels,
JP-A-59-74528 discloses a technique in which a gap material made of an insulating material with a metal coating layer formed on its surface is dispersed in an adhesive.

0004

[Problems to be Solved by the Invention] In conventional COG type liquid crystal display devices, no consideration is given to the electrical connection between the upper and lower transparent glass substrates.
When vertical conduction is established using paste, there is a problem that connection failures are likely to occur because the number of terminals is large and the size of the Ag particles is small. Particularly in the case of high-definition large screens, Ag paste has poor gap accuracy, making it difficult to provide high-quality products. In addition, when using Ag paste, in addition to the space for installing the Ag paste, space is also required for sealing material for sealing the liquid crystal and bonding both substrates, which is disadvantageous in downsizing the liquid crystal display device. .

[0005] Furthermore, when heat seals, zebra connectors, etc. are used instead of Ag paste, the structure becomes complicated, which is disadvantageous in terms of making the device thinner, lighter, and more compact.

Furthermore, in a COG type liquid crystal display device, if the upper and lower sides are not conductive, metal wiring for electrically connecting the signal side and scanning side electrodes and the liquid crystal driving LSI is provided on both the upper and lower substrates. There is a problem in that the manufacturing cost is high.

An object of the present invention is to provide a COG type liquid crystal display device which is advantageous for thinness, light weight, and miniaturization, having wiring only on one side of the substrate, providing good electrical connection between the upper and lower sides, and having a simple structure and low cost. The object of the present invention is to provide a liquid crystal display device.

[0008]

[Means for Solving the Problems] COG is an essential technology for making liquid crystal display devices thinner, lighter, and smaller. In order to improve this structure in terms of structure, cost, and reliability, a sealing material containing a conductive material was used as the vertical conduction means. That is, in the liquid crystal display device of the present invention, first and second upper and lower transparent substrates are stacked on top of each other with a predetermined gap between them, and a sealing material containing a conductive material having approximately the same dimensions as the gap is used. The two substrates are bonded together, a liquid crystal is sealed between the two substrates, an LSI for driving the liquid crystal is mounted on the first transparent substrate using chip-on-glass technology, and the conductive material is used to seal the liquid crystal between the two substrates. The transparent electrode of the substrate is drawn out onto the first transparent substrate.

[0009]

[Function] In the liquid crystal display device of the present invention, conduction is established between the upper and lower sides by means of a conductive material having approximately the same dimensions as the gap between the upper and lower transparent substrates, so connection failures are less likely to occur, good connections can be obtained, and the structure is simple, thin, and Since it is lightweight and compact, and only requires wiring on one board, manufacturing costs are low, and an inexpensive device can be provided.

Furthermore, in the present invention, since the upper and lower conductive materials are mixed into the sealing material to form a material that serves both as a conductive material and a sealing material, the required space can be reduced, which is advantageous for miniaturization.

[0011]

[Embodiment] FIG. 1 is a cross-sectional view of a main part of a COG type liquid crystal display device according to an embodiment of the present invention (cross-sectional view taken along line II in FIG. 2).
1 is a front view of the liquid crystal display device of FIG. 1, and FIG. 3 is a cross-sectional view of the conductive material.

1 is a lower transparent glass substrate, 2 is an upper transparent glass substrate, 3 is an LSI for driving a liquid crystal, 4 is a sealing material containing an upper and lower conductive material, 5 is a lower transparent electrode, 6 is an upper transparent electrode, and 7 is a metal wiring layer. , 8 is a resin material for LSI coating, 9 is a vertical conductive material, 10 is a spherical insulator, and 11 is a metal coating.

The lower transparent glass substrate 1 and the upper transparent glass substrate 2, which have different dimensions, are stacked on top of each other with a predetermined gap between them via a spacer material (not shown), and both substrates are separated by a sealing material provided around the upper transparent glass substrate 2. 4, and the space between both substrates is filled with liquid crystal and sealed. In addition, as shown in FIGS. 1 and 2, metal wiring is provided in a portion of the larger lower transparent glass substrate 1 where the upper transparent glass substrate 2 is not overlapped to electrically connect with the plurality of LSIs 3 for driving liquid crystals. 7 has been applied, and LSI3 is mounted using chip-on-glass technology. As shown in FIG. 1, a spherical conductive material 9 having a diameter almost the same as the gap between both substrates is mixed into the sealing material 4, and this conductive material 9 connects the upper transparent glass substrate. The upper transparent electrode 6 of No. 2 is electrically connected to the lower transparent electrode 5 on the lower transparent glass substrate 1 (in this embodiment, the shaded portion of the sealing material 4 in FIG. 2). That is, the upper transparent electrode 6 is drawn out onto the lower transparent glass substrate 1 via the conductive material 9, and is connected to the driving LSI 3 by the metal wiring 7. Therefore, it is possible to electrically connect all the LSIs 3 to the transparent electrodes on the signal side and the scanning side on the upper and lower sides only on the lower transparent glass substrate 1. L.S.
I3 is connected to the metal wiring layer 7 by soldering, and LS
A moisture-proof coating resin material 8 is applied on I3.

The sealing material 4 containing the conductive material is formed by mixing the conductive material into the sealing material and printing using a conventional technique. As shown in FIG. 3, the conductive material 9 includes nickel (N) on the surface of a spherical insulator 11 made of a polymer material.
i), a metal coating 10 is formed by plating gold (Au) or the like. This metal coating 10 enables conduction between the upper and lower sides. Note that the diameter of the conductive material 9 is 7 to 10 μm, the width of the sealing material 4 is 2 mm, and the thickness of the transparent glass substrates 1 and 2 is 1.1 μm.
It is mm.

As described above, in the liquid crystal display device of this embodiment, the conductive material 9 having approximately the same size as the gap between the two substrates is used to establish vertical conduction, so that connection failures are less likely to occur and a good connection can be achieved. can get. Further, since the sealing material 4 containing a conductive material is used to establish the conduction between the upper and lower sides, reliability can be further improved. Further, according to the present invention, there is no need to use heat seals, zebra connectors, etc., so the structure is simple and can be made thinner, lighter, and smaller. In addition, all the electrical connections between the signal side and scanning side electrodes and the LSI 3 can be made from one substrate (the lower transparent glass substrate 1 in this embodiment), and the metal wiring 7 only needs to be provided on one substrate. Therefore, the manufacturing cost is low, and an inexpensive device can be provided. In addition, since a conductive material and a sealing material are formed, the required space can be reduced, which is advantageous for miniaturization, and the effective area can be enlarged. Furthermore, since the conductive material is printed together with the sealing material, the number of steps can be reduced.
It is easy to manufacture and can reduce manufacturing costs.

Although the present invention has been specifically explained based on the above-mentioned embodiments, the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist thereof. be. For example, in the above example,
Although a spherical conductive material is used, a cylindrical conductive material may also be used.

[0017]

[Effects of the Invention] As explained above, in the present invention, COG
In this type of liquid crystal display device, since a sealing material containing an upper and lower conductive material having approximately the same size as the substrate gap is used, the required space can be reduced, and a good connection can be obtained, so that the required space can be reduced. Further, since wiring only needs to be provided on one substrate, manufacturing costs can be reduced. Therefore, it is possible to realize a thin, lightweight, compact, highly reliable, and inexpensive liquid crystal display device.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a main part of a COG type liquid crystal display device according to an embodiment of the present invention (cross-sectional view taken along line II in FIG. 2).

FIG. 2 is a front view of the liquid crystal display device of FIG. 1.

FIG. 3 is a cross-sectional view of the conductive material.

[Explanation of symbols]

1... Lower transparent glass substrate, 2... Upper transparent glass substrate, 3
...LCD driving LSI, 4...Sealing material containing vertical conductive material, 5
... lower transparent electrode, 6 ... upper transparent electrode, 7 ... metal wiring layer,
8... Resin material for LSI coating, 9... Vertical conductive material, 1
0...Insulator, 11...Metal coating.

Claims (1)

[Claims] 1. First and second upper and lower transparent substrates are placed one on top of the other with a predetermined gap in between, and the two substrates are bonded together using a sealing material mixed with a conductive material having dimensions approximately the same as the gap. At the same time, a liquid crystal is sealed between both substrates, an LSI for driving the liquid crystal is mounted on the first transparent substrate using chip-on-glass technology, and a transparent electrode of the second transparent substrate is connected by the conductive material. A liquid crystal display device, characterized in that it is drawn out on the first transparent substrate.